Distributed optic fiber sensors for soil deformation monitoring for construction method of box culverts being pushed to replace pipe roofs

The construction method of a box culvert being pushed to replace two pipe roofs is initiated as a city tunnel excavation method in China. This method is complex, and soil deformation is the key factor to test whether the construction method is successful or not and to guarantee the tunnel safety. The soil deformation sensors are introduced based on the distributed fiber sensing technology, their performances are tested in the laboratory, and a three-dimensional deformation monitoring network is designed according to the model tests. The test results and the monitoring data are analyzed. The soil deformation characteristics during the pipe-roofs pushing and box culvert replacement are summarized. This study will play an important role in perfecting the intelligent monitoring system, improving this construction method and analyzing the deformation of engineering soils.